In order to prevent work with a charged tool or human hands when assembling an electrical product in which a substrate including a semiconductor component (semiconductor device) (such as an IC, an LSI and a transistor), a storage apparatus, or the like, are combined, clothes or the like which remove and prevent static electricity is used. However, during assembly, an electrical product does not always have the same potential as that of the tool or a person, and there is a possibility that static electricity is accidentally discharged. The following literatures describe detection of static electricity discharge.
JP 10-12691 A discloses a technique of detecting an electromagnetic wave or discharge light of static electricity discharge due to a peeling charge generated on a substrate and detecting damage related to the static electricity discharge during manufacturing process of an electronic device (for example, a thin-film transistor liquid crystal display).
JP 2009-515171 A discloses a technique of using a voltage measuring circuit connected between a ground and a circuit substrate via a resistance to measure discharge of static electricity generated when an assembling tool is brought into contact with the circuit substrate and to thereby monitor ESD exposure of the circuit substrate.